How Secure Are Blockchain Bridges? Why Are You Attacked So Often?

Currently, the blockchain bridge is a key component of Web 3.0 and the blockchain ecosystem because it can resolve the communication problem that the earlier networks were unable to. The two main types of blockchain bridges offer distinct features, but they frequently have flaws and are used as tools by hackers to steal money. In this article, we will introduce you to blockchain bridge and go over both its benefits and security warnings. How can users handle it?

What is a blockchain bridge?

A blockchain bridge, also referred to as a cross-chain bridge, was developed to address the problems with blockchain collaboration. Due to the fact that blockchain operates in a silo and is unable to communicate with other networks, it has eventually grown to be a necessary component of the world of blockchain.

In terms of exchange, the protocol will provide credit and produce assets that are as numerous as other blockchains or as valuable as locked money. Due to the unique designs of each blockchain bridge, users are typically only able to lock their digital assets into one blockchain. For the asset exchange protocol, the locked assets will mint new coins or compute the same amount as the out-of-range blockchains.

In summary, a blockchain bridge is a device that enables the transfer of digital assets between at least two networks' blockchains. Since isolated blockchains today are unable to communicate with one another, it aims to allow users to transfer assets from one blockchain to another.

Although money transfers within the blockchain ecosystem are simple, developers still have trouble figuring out how to make the networks communicate securely.

Types of Blockchain Bridge (Trust-Based Vs. Trustless) 

Blockchain bridges can be categorized into "trusted" and "trustless" bridges based on their level of security.

A "trusted bridge," also known as a "custodial bridge," is a platform that requires third parties to conduct transactions or one where the protocol owner will act directly as a transaction inspector and custodian for users. Using a trusted bridge has the disadvantage of putting the assets under third-party supervision, making them an easy target for hackers since the custodian serves as a medium.

On the other hand, a "trustless bridge" is a platform that needs smart contracts and algorithms to store assets and complete transactions. The advantage is that users do not need to worry about risk coming from third parties or mediums because they have full control over their assets. Its vulnerability, however, depends on the completeness of the applied code. Wormhole, for example, is a platform that enables cross-network transactions between Solana and Ethereum. Wormhole was a bridge protocol between the blockchains that was harmed in February 2022 as a result of the smart contract error, allowing attackers to hack the verification process and steal money worth 326 million US dollars.

In addition, the majority of "trustless bridges" are still in the testing phase, and even professional blockchain programmers struggle to create error-free smart contract codes. Hackers have complete access to all of the users' digital currency if they can exploit or discover the trustless bridge algorithm's vulnerability. On the other hand, if a trusted bridge is used, the custodian can distribute bail in the event of a cyber-attack.

Blockchain bridge security concerns: why is it often attacked by hackers?

The blockchain bridge protocol in DeFi is the most beneficial but also the most insecure. Even though these bridges offer a decentralized financial service, they remain the center for the transfer of digital assets. Hackers may be successful in stealing a huge amount of money if they can breach the blockchain bridge.

Unlike other blockchains like Bitcoin (BTC), blockchain bridge still has many flaws and hasn't been "battle-tested" or passed a security test.

The code needed to completely connect the blockchain has not yet been developed by the bridge developers. Hackers may find holes in the bridge's smart contract if they have previous experience with coding or blockchain cryptography.

Additionally, some bridge projects have created open-source code to demonstrate transparency and build credibility. It is also a vulnerability, as it allows hackers to investigate, imitate, and attack those bridges.

Another significant issue is that most DeFi still lack supervision and KYC (Know-Your-Customer) documentation, making it simple for hackers to escape legal repercussions. Although the authorities are able to identify the hackers, there is no established legal system to bring them to justice.

How safe is the blockchain bridge for users?

Traders in the world of blockchain should be aware that blockchain bridge is a new technology with many unmanaged risks and vulnerabilities, making it the main target of hackers. However, this does not imply that all blockchain bridges are insecure; rather, it simply means that they are the most vulnerable and dangerous aspects of the ecosystem.

Cross-chain/blockchain bridge enthusiasts should therefore focus on doing their research and having a solid understanding of the protocol they have chosen, including things like "how long the protocol has been activated" and "whether it has been hacked before." Security assurance organizations should generally monitor the protocol. Users should check the project leader's data transparency and the chosen bridge's security maintenance process.

In the past, hackers have destroyed dozens of "trusted" and "trustless" bridges across the nation. For example, due to errors in the plasma bridge connecting to Ethereum, Polygon nearly lost 850 million US dollars. Fortunately, the Polygon developers have "white hat hackers" who found this mistake and alerted the team in time.

Both trusted and trustless bridges have a number of structural and technological flaws and are still unable to offer effective solutions. Additionally, hackers are coming up with new and more complicated techniques because the blockchain industry and cryptocurrency users and values are growing.

Even though errors cannot be entirely prevented, what should be done primarily for the blockchain bridge's security is probably to strictly check the source code before implementing it in order to reduce some critical flaws. Hackers may discover a way to attack if there is a small error or incorrect code.